Related Experiment Video
Updated: Jan 10, 2026
10:45
In Situ Visualization of Axon Growth and Growth Cone Dynamics in Acute Ex Vivo Embryonic Brain Slice Cultures
Published on: October 14, 2021
4.0K
Dynamics of excitability in axonal trees.
Laurie D Cohen1, Tamar Galateanu2, Shimon Marom2
1Technion-Israel Institute of Technology, Haifa, Israel; Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; Department of Neuroscience, Columbia University, New York, New York.
Biophysical Journal
|November 29, 2025
Summary
Axons reliably transmit neural signals during normal brain activity. However, prolonged or intense stimulation can cause conduction failures, especially in distant branches, revealing limits to axonal excitability.
Area of Science:
- Neuroscience
- Computational Biology
Background:
- Axons are critical for neural signal transmission.
- Axonal conduction fidelity is essential for brain function.
- Axonal conduction failures are known under high-frequency stimulation.
Purpose of the Study:
- To investigate axonal conduction fidelity under physiological and stimulated conditions.
- To determine the conditions under which axonal conduction failures occur.
- To model the mechanisms underlying axonal conduction failures.
Main Methods:
- Electrophysiological recordings in cortical neurons.
- In vitro stimulation protocols at varying frequencies and durations.
- Computational simulations of axonal conduction incorporating sodium channel dynamics.
Main Results:
- Axons maintain high fidelity spike timing transmission during complex spontaneous activity.
- Conduction failures occur at 10 Hz stimulation sustained for seconds, not at 1-4 Hz.
- Failures accumulate in distal branches with increased propagation delays.
- Simulations confirm cumulative sodium channel inactivation as a key mechanism.
Conclusions:
- Axons are highly reliable under physiological conditions.
- Prolonged or high-frequency stimulation reveals axonal excitability limits.
- Understanding these limits is crucial for comprehending sustained neural drive and pathological states.
Related Concept Videos
01:21Neurons: The Axon
6.8K
Axons are long, cytoplasmic processes of nerve cells capable of propagating electrical impulses known as action potentials. The cytoplasm or axoplasm of an axon contains neurofibrils, neurotubules, small vesicles, lysosomes, mitochondria, and various enzymes, all encased within the axolemma, the plasma membrane of the axon.
The axon attaches to the cell body at a cone-shaped elevation called the axon hillock. The initial part of the axon, closest to the hillock, is known as the initial segment....
The axon attaches to the cell body at a cone-shaped elevation called the axon hillock. The initial part of the axon, closest to the hillock, is known as the initial segment....
6.8K
01:19The Role of Ion Channels in Neuronal Computation
3.6K
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
3.6K
01:41Action Potentials
141.0K
Overview
141.0K
01:14Action Potential
10.6K
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
10.6K
01:31Action Potential
4.2K
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
4.2K
01:23Propagation of Action Potentials
8.8K
The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
8.8K